Algebra-1

Question Analysis
This question assesses the student's ability to handle negative and fractional common ratios in the explicit formula for the nth term of a geometric sequence. The given values are the first term and the common ratio , and the student needs to find the 4th term.

Key Concept Explanation
The explicit formula for the nth term of a geometric sequence is (). This formula is applicable even when the common ratio is negative or a fraction.

Step-by-step Solution
1. Identify the given values: , , and .
2. Substitute these values into the explicit formula: